langs a-z

Task/Anonymous-recursion/CoffeeScript/anonymous-recursion.coffeescript

@@ -0,0 +1,17 @@
+# This is a rather obscure technique to have an anonymous
+# function call itself.
+fibonacci = (n) ->
+  throw "Argument cannot be negative" if n < 0
+  do (n) ->
+      return n if n <= 1
+      arguments.callee(n-2) + arguments.callee(n-1)
+
+# Since it's pretty lightweight to assign an anonymous
+# function to a local variable, the idiom below might be
+# more preferred.
+fibonacci2 = (n) ->
+  throw "Argument cannot be negative" if n < 0
+  recurse = (n) ->
+      return n if n <= 1
+      recurse(n-2) + recurse(n-1)
+  recurse(n)